Helmet



FIG. 1 is a front perspective view of a helmet in accordance with our new design; and,

FIG. 2 is a left-side elevational view of the helmet shown in FIG. 1.

The broken lines depicting a person's head represents environmental subject matter that forms no part of the claimed design. The broken lines immediately adjacent the shaded areas on the helmet represent the bounds of the claimed design while the remaining broken lines are directed to portions of the helmet that form no part of the claimed design. 

CLAIM The ornamental design for a helmet, as shown and described. 